<style>
    .modal-sm {
        margin-top: 100px !important;
        width: 326px;
    }
</style>
<div style="border-width: 2px; border-color:white; padding:12px; width: 326px;">
    <div id="qrcode"></div>
    <div class="text-center">
        <h3>微信扫一扫</h3>
    </div>
</div>